Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"eggs and larvae"”.
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Development of bubble screen barriers for controlling dispersal of invasive carp eggs and larvae in streams
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-12-01
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The effect of turbulence on survival, dispersal, and swimming behavior of grass carp eggs and larvae
There is an urgent need to monitor and control the spread of invasive grass carp (Ctenopharyngodon idella) in North America. Grass carp are reproducing in tributaries to Lake Erie and control efforts targeting reproduction are greatly needed. Current strategies for their control and removal are …
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Modelling the effects of spatio-temporal spawning variability on the transport and retention success of sardine (Sardinops sagax) eggs and larvae around South Africa
The transport and retention of sardine (Sardinops sagax) eggs on the west and south coasts of South Africa were investigated using a Lagrangrian, particle tracking, individual-based model (IBM), coupled with two 3-D hydrodynamic Regional Ocean Modeling System (ROMS) model configurations of …
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THE MICROBIOME AND THE REPRODUCTIVE ECOLOGY OF Dermacentor variabilis AND Dermacentor andersoni IN WESTERN CANADA
… of the Rocky Mountain wood tick, Dermacentor andersoni, and the American dog tick, Dermacentor variabilis, are largely allopatric on the Canadian prairies. Range expansion by D. variabilis to the north and west has resulted in an area of sympatry in south-western Saskatchewan, where both tick …
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Modeling the effects of environmental and ecological processes on the transport, mortality, growth and distribution of early stages of Cape Anchovy (Engraulis Encrasicolus) in the Benguela system
… approach was used to study environmental factors and processes influencing the early life history of anchovy in the southern Benguela region and on the Agulhas Bank. The intention was to then establish the link between these factors and processes and the recruitment success of anchovy in the …
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REPRODUCTION IN FATHEAD MINNOWS (PIMEPHALES PROMELAS) FOLLOWING WATER OR SEDIMENT EXPOSURE TO A COMPLEX URANIUM MILLING EFFLUENT ELEVATED IN SELENIUM
… elevated concentrations of nutrients, compounds and many metals including the metalloid selenium (Se). Selenium has the potential to bioaccumulate in aquatic systems even when water concentrations are low, which has resulted in the identification of Se as a constituent of concern in affected …
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Field and laboratory studies suggest that recruitment of the invasive common carp is controlled by native fish in Stable Lakes of the Upper Mississippi Basin.
… of carp is limited by native predatory fish and that carp are only able to recruit in habitats where these native species have been excluded due to winter hypoxia. We tested this hypothesis by comparing the survival of carp eggs and larvae in the presence and absence of native predatory …
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Modelling the oceanographic transport of young Cape anchovy Engraulis capensis by advective processes off South Africa
… flow alters the likelihood of offshore advection and hence losses of anchovy from the system. Two different approaches have been taken to address the effects of altered advection, and the applicability of each is discussed. One approach involves altering westward advection in proportion to the …
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An individual-based modelling approach to examine life history strategies of sardine Sardinops sagax in the southern Benguela ecosystem
Hypotheses regarding the spawning strategy and recruitment of sardine (Sardinops sagax) in the southern Benguela ecosystem are tested using an individual-based Lagrangian particle tracking model linked with a 3-D hydrodynamic model of the region. Experiments focus on the dispersion of eggs and …
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Investigations into some important fish larvae in the south east Atlantic in relation to the hydrological environment
… seasonal hydrological changes in the survey area and a comparison between years. (ii) an examination of the seasonal distribution and abundance of the larval stages in relation to hydrological conditions. (iii) the determination of the preferential temperature and salinity ranges for the larvae. …
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Ecological and logistical considerations toward introducing Heringia calcarata to New Zealand
… of a collaborative project between Virginia Tech and Plant and Food Research New Zealand (PFRNZ) to introduce Heringia calcarata (Loew) (Diptera: Syrphidae) to New Zealand (NZ) for biological control of woolly apple aphid (WAA), Eriosoma lanigerum (Hausmann) (Hemiptera: Aphididae). Ultimately, the …
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Egg and larval ecology of anchovy (Engraulis capensis) and sardine (Sardinops sagax) in the Southern Benguela ecosystem
Temporal and spatial changes in the abundance and distribution of anchovy and sardine eggs and larvae in the southern Benguela ecosystem were investigated during 14 cruises over 2 consecutive summer upwelling seasons as part of the South African Sardine and Anchovy Recruitment programme (SA-SARP). …
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Reproduction And Propagation Of The Neosho Mucket, Lampsilis Rafinesqueana
… system in SE Kansas, NE Oklahoma, NW Arkansas and SW Missouri. Timing of reproduction was compared at two sites in the Spring River system: Shoal Creek at Joplin, MO and Spring River at Carthage, MO. Monthly samples of 6-30 individuals were examined at each site in 2001 for the presence of …
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A procedure for the computation of sea surface advection velocities from satellite thermal band imagery, with applications to the South East Atlantic Ocean
… to the oceanic regions around South Africa and cognisance had to be taken of restrictions imposed by the specific oceanographic conditions, availability of satellite data, as well as the capabilities of the image processing system used. As a first step, a set of image navigation algorithms …
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Fish spawning strategies in the variable southern Benguela Current region
… Benguela. Current system between August 1977 and August 1978. Plankton was collected at each station by means of a double oblique tow behind the ship at 2 knots down to 100m or 5m off the bottom. Plankton displaced volume was determined and all fish eggs and larvae were removed and identified …
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Evaluation of the biological feasibility of white stumpnose, Rhabdosargus globiceps, as a potential aquaculture candidate in South Africa
Sustainable diversification and the biological viability of selected aquaculture species are now viewed as being crucial factors that must be assessed in order to introduce the candidate species into commercial production. The biological feasibility of white stumpnose, Rhabdosargus globiceps,as a …
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Water relations of the endemic New Zealand frogs Leiopelma archeyi, L. Hamiltoni and L. Hochstetteri
Aspects of habitat and water balance physiology were compared between the endemic and anatomically primitive New Zealand frogs Leiopelma archeyi, L. hamiltoni and L. hochstetteri. Field studies in an area of the Coromandel Range showed that the partially sympatric L. archeyi and L. hochstetteri had …
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Trophic relevance of gelatinous zooplankton for commercial fisheries in the Irish Sea
… with fish for food resources, or feed on fish eggs and larvae. They also provide habitat and space for developing larval and juvenile fish which use their hosts as means of protection from predators and feeding opportunities. However, the broader ecological relevance of jellyfish is often …
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IMPROVING THE ASSESSMENT OF SPREAD AND IMPACTS OF FRESHWATER INVASIVE SPECIES
… but they host 6-10% of global biodiversity and are considered endemism hotspots. Moreover, they provide ecological services for more than 6 billion people worldwide, thus their conservation is particularly relevant to preserve both biodiversity and human well-being. Despite their importance, …
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How marine organisms cope with changing climate
… continue to rise, the oceans are becoming warmer and more acidic. Organisms need to adjust to such environmental changes and display a variety of mechanisms to maintain their fitness in novel conditions. These adjustments can operate at various levels of biological organisation: from cellular …
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